CLPEX Chat Board

I processed an item with amido black and developed a print - identified it and now I am trying to write the report. It is very important to the case that this print was in blood. I am hesitant to say that the print was in blood (even though I know it is) in a report. I have tried to find info on what else amido black could react with to no avail. Does anyone know where I can find what else could react with AB? Does anyone else report out that a print was in blood without having it confirmed by a biologist?

maybe say 'apparent blood' or 'possible blood' and note any presumptive test and/or further exam to confirm it is blood....

It's important to limit descriptions to things you're qualified and equipped to establish. What matters here is that you chose a particular technique because what you found was consistent, in your experience, with blood, and that it developed an impression. Anything else is unimportant to the basic process of discovering and preserving the impression. If the exact nature of the substance is an issue, it's properly an issue for other specialists to determine. You're unassailable on your own ground, and the results are there. You can honestly say that you believe it to be blood because it reacted as blood would to the reagent, but you aren't presenting that believe for anything other than to explain how you processed the evidence for your limited purpose, and that description provides any other specialist, such as a serologist, with anything they need to know about the history of the evidence.

Amido Black is a protein stain, and is such should not be considered as even a presumptive test for blood, let alone a confirmatory test. The protein may be present in other body fluids, in addition to blood. However, other actual presumptive tests may be successful after the application of amido black. I'm not sure about confirmatory tests without some research. Sorry, don't have time for citations right now.

Unless you have the experience & expertise, & have done the proper testing, your report should be limited to something along the lines of 'having the appearance of blood', or if someone known to you to have the necessary qualifications has tested the substance, 'reported to be blood'.

Tavernaro is correct. Amido Black is a protein stain, and you would need something that reacted with hemoglobin to say that it is blood. If you still have the evidence you could do a presumptive test with Kastle-Meyer or O-Tol or a confirmatory with a Takayama microcrystal test or an Ouchterlony test (which is species specific).
Outside of that you would just have to say it resembled and responded as blood would have.

An article published yesterday shows the dangers of assuming Amido Black is a blood indicator. There are already over 690 article on this case. I've linked a few and pulled out a couple of relevant quotes.

http://www2.nbc4i.com/cmh/news/local/ar ... ure/20543/

All charges against Lewis were dropped Thursday after it was revealed that a bloody handprint found on the wall of the Lewis home was not blood after all.

http://www.10tv.com/live/content/local/ ... ml?sid=102

The palm print that was found in the bedroom turned dark blue because of a chemical test that led police to believe the print was in blood.

"The point is that it reacted with the Amido Black, which is the indicator that it's blood," Mathias said.

http://www.google.com/hostednews/ap/art ... wD99U8ETO0

The location of the print on a blood-covered wall and the print's reaction to a crime analysis chemical made them believe the print itself was bloody, said Cmdr. Mary Mathias and Lt. Tom Fischer.
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It's really too bad that someone had to spend 18 months in jail because the fingerprint evidence was overstated (instead of taking the time to test the hypothesis that it was blood).

There have been quite a few errors this year and I keep thinking about a presentation Ron Smith's gives. I think it's called, "What Happened to Getting it Right?" I would hope that the fear of being the next agency or examiner in the paper would encourage people to be more careful and more thorough.

Based on Michele's post, I guess my question then is: when do we know we are right or wrong if what we observe goes along with what we have been trained to believe (in reference to blood reagents and latents). Everything that I have read states that blood reagents, such as LCV and amido black, will not react to the "normal" constituents of latent residue, but instead react with proteins, etc., which can be found in blood.

Using one (or more) of these reagents precludes the use of phenolphthalein for a presumptive blood test. More sophisticated DNA typing is possible, but if a profile is obtained, that doesn't mean that the latent was in blood. Is there a test that says, "yes, absolutely, that is blood." And, what is the benefit of running this test instead of, or in addition to, traditional DNA tests?

If I develop a latent print using amido black on a surface where there was no visible ridge detail prior to the application of the blood reagent, what can I say, or should I say, about that latent? Should there be nothing said of the possibility that it is blood? I certainly do not want to be in a position to overstate evidence, particularly as a print made in blood would most likely be significantly more probative in some situations than one made in "normal" latent print residues. And, how does an examiner who errs on the side of caution in explaining to another department member that the print was developed using a blood reagent but the print's matrix is unknown, prevent that other person from making assumptions about the latent in question?

Out of curiousity, in one of the article's linked, it mentions that the accused's (Derris') DNA was not found in the print. Obviously all of the information can not be covered in a single news article, but was any DNA found in the print? I would have thought that they would be looking for the victim's (Dennis') DNA, not the accused's DNA.

Heather,

I think Amido Black is use so often with prints left in blood that it’s become known as a blood reagent even though it’s not. Amido Black is a protein reagent… blood is just one of the matrixes that Amido Black reacts with. To prevent others from assuming the print was left in blood, I’d call Amido Black a protein stain, instead of calling it a blood reagent.

Another common misunderstanding is that presumptive tests can establish the presence of some material (blood, drugs, etc). Presumptive tests can show that a substance is possibly what you’re testing for, but presumptive tests are not conclusive, further testing is necessary to establish what the substance actually is. You asked, how do we know absolutely? As an LPE, we don’t. It has to be tested by someone who specializes in testing substances. In our lab, we don’t send out latent prints to be tested, we just recommend to the detective that it be sent to our state lab. As an LPE, I wouldn’t testify to the matrix of a latent print. I would only say that I chose to process with Amido Black because the latent print appeared to be left in blood. The Amido Black reacted with the substance but that doesn’t mean it was blood (Amido Black reacts with other substances as well). As a side note, Ninhydrin is a protein stain also but I doubt that examiners would say that a reaction meant the matrix was left in blood. The only way to know what the print was left in is to have it tested.

It would probably be a good idea to have trainees tests Amido Black on different items during their training so they understand all the different things that Amido Black can react with.

In this case, I don’t know if any DNA was found in the print but the victim and the accused would have had the same DNA (since they were identical twins).

If you're speaking as a latent print person, the answer is the same as it is for every sort of specialist. No one should be working in a crime scene or handling evidence who hasn't been trained in the basics of every sort of physical evidence. That means knowing the nature of each sort, how it is deposited, the general nature of all the ways in which each sort can be developed as evidence, and how each evidentiary aspect can be destroyed. Each specialist has to know how their particular methods can damage evidence for purposes outside their specialties. The alternative is that all the scene work is supervised by someone who possesses that knowledge and having someone with broad knowledge making decisions in the lab. (Of course this happens naturally on CSI where everyone is an adept at everything.) If choices have to be made, at least they are made by someone equipped to make them appropriately.

I consider control of the entire scene by a specialist/generalist to be the best bet. The entire scene is one big object, and the interactions of complex evidence and what human technicians do to it is best handled by someone who isn't focused on one discipline. But that's also an ideal that's not available everywhere. That means that broad basic training for everyone is necessary.

Taking the example case, a structured approach to the evidence would have made them conscious of its potentials for identification as human blood or other specific fluid, determination of the source of a bodily fluid through DNA, identification of the agent by fingerprint identification, inferences of body position and orientation at the time of deposit, and possible association with cast-off and other blood pattern evidence. Each potential requires different specific collection, documentation, and analysis. None of the required knowledge is highly technical, nor does it require a single technician to be adept at handling all aspects of the evidence. To the degree that such knowledge is not present and applied, evidence products can be lost. I think it's safe to say that in most places, it's not present and applied.

Michele,

I think it was too late last night when I posted. I overlooked the fact that the two were identical twins and the DNA would have been the same. That was a stupid oversight on my part.

I like the idea of calling amido black a protein stain instead of a blood reagent. I also understand the concept of it being presumptive only, requiring additional analysis for more conclusive results. In the few cases that I have used amido black at a scene or in the lab, the Biology Unit refers to my use of the chemical as the presumptive test for their purposes, and then further DNA analysis is performed.

Michele, an additional question for you, if I may. You mention that as an LPE, you would not testify to the matrix of a latent print. We have discussed this in my Unit, and the consensus is that we would basically have to guess the matrix of most prints, as we can't really know without additional testing. With the new Draft for Comment from SWGFAST, it is being recommended that the matrix for each latent impression be documented. What is your feeling on this?

Heather,

It's funny you should mention the SWGFAST draft, that's were our office discussion went as well.

I'm guessing that this was intended to simplify the standards (by saying to note the matrix), but sometimes oversimplifying ideas just creates mis-information and wrong information. If I processed the item then I'd know it was black powder and could document that. In our office, we'd document this in our processing notes and not in our comparison notes. If someone else processed the item and I just received the latent print card then I could write that the lift is consistent with the appearance of black powder but I really don't know for sure. Ashbaugh use to teach documentation in his classes but he wasn't recommending this for every case. If I remember correctly (it was along time ago), I thought he did different types of documentation depending on what was needed in each situation. What I took away from his class was that an examiner should pay attention to the different features (matrix, substrate, pressure, etc) to see if it was consistent with the facts of the case. I really don't remember him recommending this for every case. Again, in our office, we look at these elements and document anything abnormal. As an example, once I had two latents in a case that were obviously multiple lifts of the same latent print. When I looked at how the officer described it on the lift cards, I found that he wrote that they were from different objects. Since this type of thing isn't normal, I noted it in my case report (after calling Pat Wertheim for advice).

My notation of this fact hindered the use of the latent print evidence in this case but I think it was better for the prosecutor to know this up front, rather than to find out later. The officer that lifted the print wasn't pleased with my discovery but he learned the importance of labeling his lift cards immediately. I've also learned some of my biggest lessons by making mistakes, I guess there's a lot to be said for making a lot of mistakes.